Additive manufacturing and applications thereof through thermo-mechanical treatment of defective parts

Abstract

The technologies disclosed herein relate to systems and methods of manufacturing an alloy. In accordance with various embodiments, the alloy produced via the disclosed systems and/or methods include engineering of duplex microstructures in the alloy to improve poor mechanical performance of additive manufactured metals. In various embodiments, the alloy may be subjected to thermo-mechanical treatment where simultaneous heat and pressure is applied with a deliberately high density of fusion defects. In accordance with various embodiments, the systems and methods disclosed in the present application have the potential to improve damage tolerance of critical structures experiencing fatigue loading and impact loading.

1 . A method of manufacturing an alloy, comprising:
 forming a pre-product having a first plurality of columnar grains and a first plurality of globular grains;   performing a thermo-mechanical treatment of the pre-product; and   transforming some of the first plurality of columnar grains of the pre-product into additional globular grains to obtain the alloy comprising a second plurality of columnar grains and a second plurality of globular grains.   
     
     
         2 . The method of manufacturing according to  claim 1 , wherein the second plurality of columnar grains comprises fewer columnar grains that the first plurality of columnar grains, and the second plurality of globular grains comprises more globular grains than the first plurality of globular grains. 
     
     
         3 . The method of manufacturing according to  claim 1 , wherein the first plurality of columnar grains comprises a high density of fusion defects. 
     
     
         4 . The method of manufacturing according to  claim 3 , wherein a size of the fusion defects ranges between about 50 μm and about 500 μm. 
     
     
         5 . The method of manufacturing according to  claim 1 , wherein the pre-product comprises an average porosity ranging between about 15% and about 32%. 
     
     
         6 . The method of manufacturing according to  claim 1 , wherein the thermo-mechanical treatment comprises hot isostatic pressing (HIP). 
     
     
         7 . The method of manufacturing according to  claim 1 , wherein the transforming of some of the first plurality of columnar grains of the pre-product into the additional globular grains occurs via a dislocation-driven recrystallization process during the thermo-mechanical treatment. 
     
     
         8 . The method of manufacturing according to  claim 1 , wherein the alloy comprises one of steel, Ni-based superalloys, Al-based alloys, or Ti-based alloys. 
     
     
         9 - 20 . (canceled) 
     
     
         21 . The method of manufacturing according to  claim 1 , wherein the alloy comprises a titanium aluminum vanadium alloy. 
     
     
         22 . The method of manufacturing according to  claim 21 , wherein the titanium aluminum vanadium alloy is Ti-6Al-4V. 
     
     
         23 . The method of manufacturing according to  claim 1 , wherein the additional globular grains comprise up to 110% of the first plurality of globular grains. 
     
     
         24 . The method of manufacturing according to  claim 1 , wherein at least a portion of the second plurality of the globular grains is defect-free. 
     
     
         25 . The method of manufacturing according to  claim 1 , wherein the forming of the pre-product is performed via additive manufacturing. 
     
     
         26 . The method of manufacturing according to  claim 23 , wherein the additive manufacturing comprises a laser-based selective laser melting or a plasma-based additive manufacturing. 
     
     
         27 . The method of manufacturing according to  claim 23 , wherein the forming of the pre-product is performed at a low energy density to produce the pre-product within a lack-of-fusion regime during the additive manufacturing. 
     
     
         28 . The method of manufacturing according to  claim 1 , wherein the alloy has a failure strain of at least 15%. 
     
     
         29 . The method of manufacturing according to  claim 1 , wherein the alloy has a failure strain between 90% and 300% of a failure strain of the pre-product. 
     
     
         30 . The method of manufacturing according to  claim 1 , wherein the alloy comprises the second plurality of columnar grains in a form of laths, and at least a subset of the second plurality of globular grains are surrounded by at least a portion of the laths. 
     
     
         31 . The method of manufacturing according to  claim 1 , wherein a first difference between a failure strain of the alloy and a failure strain of the pre-product is greater than a second difference between a tensile strength of the alloy and a tensile strength of the pre-product. 
     
     
         32 . (canceled) 
     
     
         33 . An alloy manufactured according to the method of  claim 1 .